Remote inductive sensing uses a sensor resonator with a remote sense inductor coupled to a resonator capacitor through a shielded transmission line. The T-line includes a signal line and a shield return line: the sense inductor is connected at a T-line sensing end between the signal line and the shield return line, and the resonator capacitor is connected at a T-line terminal end to at least the signal line. An inductance-to-data converter (IDC) is connected at the T-line terminal end to the signal line and shield return line (set to a common mode voltage). In operation, the IDC drives oscillation signals over the signal line to the sensor resonator to sustain a resonance state, with the sense inductor projecting a magnetic sensing field, and converts changes in oscillation drive signals, representing changes in resonance state resulting from a sensed condition, into sensor data corresponding to the sensed condition.

A power tool including a motor and an impact mechanism. The impact mechanism is coupled to the motor and includes a hammer driven by the motor, and an anvil positioned at a nose of the power tool, and configured to receive an impact from the hammer. The power tool also includes a sensor assembly positioned at the nose of the power tool, and an electronic processor. The sensor assembly includes an output position sensor configured to generate an output signal indicative of a position of the hammer or the anvil. The electronic processor is coupled to the output position sensor and to the motor, and is configured to operate the motor based on the output signal from the output position sensor.

A displacement sensor includes a coil, an inverter electrically connected to the coil, the inverter being configured to generate an oscillation signal, a reducer electrically connected between the coil and an output terminal of the inverter, the reducer being configured to reduce the strength of the oscillation signal, and a frequency detector electrically connected to the inverter, the frequency detector being configured to detect an oscillation frequency of an oscillator circuit in response to a distance between a measurement target and the coil, the oscillator circuit including the coil, the inverter, and the reducer and having an oscillation frequency of 30 MHz or higher.

A sensor arrangement for determining at least one physical parameter of a sensor unit which is activated by at least one periodic excitation, comprising a detection region in which changes of the parameter in the surroundings of the sensor unit lead to an output signal from the sensor unit. The sensor unit is wired such that if there is no change of the parameter in the detection region the output signal is a zero signal at the output of the sensor unit, whereas if there are changes of the parameter in the detection region the output signal is a signal that is not zero and which has a specific amplitude and phase. By means of a closed-loop control, the non-zero signal in the receive path is adjusted to achieve an adjusted state at zero even in the presence of changes of the parameter in the detection region. Inherent in the control signal used for this adjustment is a deviation (x, y) of the control signal from the adjusted state, which deviation represents information about the parameter. To create a sensor arrangement and a method in which values of a physical parameter in a detection region can be clearly determined, in a four-quadrant representation of the deviation (x, y) in the form of a vector analysis in a phase space of the control signal, the angle of an imaginary vector (2.6) relative to the x axis of an x, y coordinate system, said vector leading from the origin (2.7) of the x, y coordinate system to a measuring point (2.5) and said origin corresponding to the adjusted state, represents a measurement for the change of the parameter along a direction, and/or the magnitude of the imaginary vector (2.6) represents a measurement for the change of the parameter along a further direction.

An apparatus for detecting a position of a rotor of a DC motor with N phases having a plurality of windings. The apparatus includes circuitry to couple at least two of the windings between a supply voltage and a reference voltage according to a first current path and allow the current stored in the two windings to be discharged through a second current path. The circuitry is configured to force the at least two windings at a short circuit condition in the second current path. The apparatus also includes a measurement circuit configured to measure the time period of discharging the current stored in the two windings and a rotor position detector for detecting the rotor position based on the measured time period.

A method of path measurement uses eddy current principles and a sensor which interacts with a measuring object. The sensor has an electrical connector and a sensor coil. In accordance with the method, an operating voltage is applied to the sensor such that a magnetic field is built up by an oscillator in cooperation with the sensor coil. A measuring object may be moved in the vicinity of the sensor coil through an opening in the sensor coil to produce field strength changes adjacent to the coil and the oscillator. The field strength changes are detected by an evaluation circuit and transmitted to a microcontroller. The microcontroller processes the signals of the evaluation circuit and provides the evaluation circuit with said signals via an output and protection circuit. The sensor coil consists of a plurality of windings constructed in a planar manner.

A method of manufacturing a proximity sensor and a manufacturing system for the proximity sensor capable of improving detection precision or expanding a detectable range are provided.

A method of manufacturing a proximity sensor outputting presence or absence of a detection object or a position of the detection object as a detection result is provided. The manufacturing method includes: disposing the proximity sensor in a temperature-changeable environment; setting an environment of the proximity sensor to a plurality of different temperatures respectively and storing temperature detected by the temperature detection part of the proximity sensor in association with the detection result output by the control calculation part at each temperature; determining a characteristic parameter unique to a target proximity sensor based on the stored temperature and detection result; and setting the determined characteristic parameter for the target proximity sensor.

An apparatus for sensing a rotating body includes a plurality of units to be detected provided on the rotating body; at least two sensing coils disposed to face the units to be detected; an oscillating unit including at least two capacitors respectively connected to the at least two sensing coils to form at least two oscillation circuits; and a rotation information calculator configured to count frequencies of at least two oscillation signals respectively output from the at least two oscillation circuits to generate a first count value and a second count value, and calculate a rotation direction of the rotating body based on a change in the first count value and a change in the second count value.

A variable inductor direction sensor may include a rotatable body having a first circumferential tooth array and a stationary body having a second circumferential tooth array. The second circumferential tooth array may be concentric with the first circumferential tooth array. The rotatable body may be disposed relative to the stationary body such that one of the first circumferential tooth array and the second circumferential tooth array circumscribes the other of the first circumferential tooth array and the second circumferential tooth array. Further, at least one of the first circumferential tooth array and the second circumferential tooth array has a non-uniform circumferential geometry.

Systems and methods for detecting a plunger movement condition with respect to a solenoid coil are described. A method may include generating a first derivative signal waveform of a current flowing in the solenoid coil, identifying whether there is at least one zero crossing point in the first derivative signal waveform, and detecting the plunger movement condition according to an identification result indicating whether there is at least one zero crossing point in the first derivative signal waveform.